Switch and signal control system for railroads



M 1944- N. D. PRESTON arm. 2,344,728

SWITCH AND smmu. CONTROL svswm FOR RAILROADS Filudbct 20, 1942 8 Sheets-Sheet 1 INVENTOR s Nmgeston and FBHitchcock THEIR ATTORNEY N. D PRESTON E'I'AL March 21, 1944.

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed 001:. 20, 1942 8 Sheets-Sheet 2 INVENTORS Weston and FhHikhcoc M M. M

I; z 6Q ND BY THEIR A'ITORNEY T: [t m March 1944' N. D. PRESTON a-rm. 2,344,723

swmcn AND smrm. 001mm. SYSTEM FOR RAILROADS Filed Oct. 20, 1942 8 Sheets-Shut 3 INVENTORS Nq reston 1nd EBH flchctock THEIR ATTOR'NEY March 4- N. n. PRESTON ET AL ,34 3

SWITCH AND SIGNAL CONTROL SYSTEM FOR HAILROADS Filed 001;. 20, 1942 8 Sheets-Sheet 4 U5 \Hfi;5$.

NlCR ZRCR L i in o q INVENTOR: g ungyeato flazfinmchmk 9 THEIR ATTORfiEY March 21, 1944. E T N AL 2,344,728

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Oct. 20, 1942 8 Sheets-Sheet 5 F u l 3 L I g p- I A 0 I E: E i 41 l l "H J 0 N L {1 g 4,: 2 7? s--- 0 INVENTORS f'fi qff fi a NTDI reSton and EBHitchmck a 8 m5 3 a $5 THEIR ATTORNEY March 21, 1944.

N. D. PRESTON ET AL.

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Oct. 20, 1942 8 Sheets-Sheet 6 INVENTORS NDgresTon and FD Hitchcock THEIR ATTORNEY March 9 N. o. PRESTON ETAL 2,344,723

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS M -w I MFR 45ML Nlgreston and FBHiCchcoch THEIR ATTOR-NEY Patented Mar. 21, 1944 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Neil D. Preston and Forest B. Hitchcock, Rochester, N. Y., assignors to General Railway Signal Company, Rochester, N. Y.

Application October 20, 1942, Serial No. 462,686

9 Claims.

This invention relates to switch and signal control systems for railroads, and it more particularly pertains to the provision of control panel indications tor a control machine in a switch and signal control system of the entrance-exit type.

This invention is an improvement over the indication system disclosed in the prior patent to T. J. Judge, No. 2,298,946, granted October 13, 1942, and no claim is made herein to that which is disclosed in such patent. The NZ system disclosed in that patent and in the present application is for a track layout having a plurality of conflicting routes and comprises a miniature diagram of the track layout at a control ofilee along which is disposed control buttons for manual designation of the corresponding entrance and exit ends of routes'desired to be established through the track layout. Responsive to the designation by an operator or the respective entrance and exit ends of each route desired to be established, switch position selecting relays are conditioned to cause the power operation of the respective track switches to establish the desired route. This type of an entrance-exit system is based upon principles making it readily adaptable to practically any track layout, there being a definite number of switch position selecting relays per single track switch or per crossover, irrespective of the number of track switches included in any given route.

An object of the present invention is to provide an improved system of indicating on the control panel of the control machine at the control cmce distinctively such conditions as routes established, train occupancy of track sections, the normal or reverse positions of track switches, and the out-of-correspondence condition oi the track switches. According to the present invention these conditions are indicated by the selective illumination of linear portions of the trackway oi the track diagram so as to form a substantially continuous line of light corresponding to each route established, such line oi light changing to a distinctive color for portions occupied by a train passing through theroute,

and being extinguished for the track sections that become unoccupied in the rear of the train in accordance with the restoration of rear release route locking for the various track sections asthey become unoccupied in the rear of: the train. 4 Another objector the present invention is to reduce to a minimum the number of relays required to provide the desired indications by con trolling the indicator lamps associated with indicating routes established but unoccupied from a circuit network organization having circuit portions selected by the switch position selecting relays associated with route establishment, and having energy feed points corresponding to the exit ends of the route. This circuit organization involves the use of track relay contacts in the circuit network for the energization of the indicator lamps in such a manner as to remove energy from the route indicator lamps for portions of routes which become unoccupied in the rear of trains for either direction of trafilc, thereby preventing flashes of the lamps upon restoration of the track relays subsequent to the restoration of the switch position selecting relays as the various track sections become unoccupied in the rear of trains and the rear release route locking is restored. By this arrangement special indication relays employed in the above mentioned Judge patent are not required.

Another object of the present invention is to indicate distinctively the unlocked position of a track switch when it becomes abnormally unlocked as compared to the track switch becoming unlocked in the normal course of its power operation from one position to the other.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings and in part pointed out as the description of the invention progresses.

,In describing the invention indetail, reference will be made to the accompanying drawings in which like reference characters designate corresponding parts throughout the several illustrations, in which those parts having similar features and functions are designated by like letter reference characters which are generally made distinctive by reason of preceding numerals belonging to various switch and signal locations, and in which:

Figs. 1A and 1B when placed side by side respectively illustrate the route establishing means provided for the track layout of this embodiment of the present invention;

Fig. 2 illustrates in detail circuits appertaining to the control of track switches and signals for a typical portion of the track layout of this embodiment of the present invention;

Fig. 3 illustrates the circuits employed for the control of the signals in accordance with the establishment of routes;

Figs. 4A and 4B illustrate the track layout and signals governed by the switch and signal control system for this embodiment of the present invention, Fig. 4B illustrating as typical of each of the signals how relays repeating the proceed and stop po'siti'onsof a particular signal are controlled;

Fig. 5 illustrates a form of electric locking that can be applied to the entrance-exit system of this embodiment of the present invention; and

Figs. 6A and 63 when placed side by side show the track diagram on the front of the control panel together with circuits for the control of the indicator lamps secured behind the panel for providing the line of light indications.

The illustrations for the disclosure of the present invention have been prepared for the purpose of facilitating the disclosure of the present invention as to the mode of operation and the principles involved rather than for the purpose of illustrating the construction and arrangement of parts as they would be employed in practice. Thus the various relays and their contacts are shown in a conventional manner and certain relay contacts are shown in conventional written circuit form for the purpose of simplifying the illustrations, each of the contacts thus shown being readily identified with its relay by the use of the corresponding relay reference character above such contact.

The symbols and are employed to indicate the respective positive and negative terminals of suitable batteries or other sources of direct current and the circuits with which those symbols are used always have current flowing in the same direction. The symbol (F'+) is used to indicate a connection to a battery or other source of direct current through an interrupter. If alternating current is used for the energization of the indicator lamps the symbols and are to be considered as connections to a source of alternating current having corresponding instantaneous polarity.

Reference is made from time to time during the description of the present invention to the function of parts of the system of a similar nature or class by reference to the letter reference characters common to all of such parts, and such reference is to be considered as applicable to any of the parts of the system illustrated in the drawings which are designated by such letter reference characters together with the distinctive preceding numerals.

For the purpose of simplification of the present disclosure reference is to be made to the above mentioned patent to T. J. Judge, No. 2,298,946, granted October 13, 1942, for the detailed description of the apparatus and the mode of operation of the system in the establishment of routes, and it is therefore believed suflicient for an understanding of the present invention to consider only in a general manner the operation of the system as to the establishment of routes. For the purpose of making the description of the above mentioned Judge patent readily applicable to this case for a disclosure of the route establishing means, similar reference characters and figure numbers for the drawings relative to that part of the disclosure have been used.

The track layout for this embodiment of the present invention has been chosen to correspond with a portion of the track layout in that Judge patent therein termed as an interlocked group. Although the present invention is illustrated as applied to this particular relatively simple track layout, it is to be understood that the system is readily applicable to practically any track layout to be encountered in railway practice because of the standard arrangement of circuits provided in a typical manner for each of the various crossovers, single track switches, and route ends.

It is to be understood that various accepted types of signals can be employed in connection with the system, and it will be assumed for this embodiment of the present invention that searchlight signals, such, for example, as the signal disclosed in the patent to O. S. Field, Patent No. 2,239,316, dated April 22, 1941, are employed. The signalling arrangement for this embodiment of the present invention corresponds to that shown in the above mentioned Judge patent except that the call-on signals have been eliminated for the purpose of simplification. It is to be understood that the track switches are power operated in accordance with routes selected by the self-selecting circuit networks in accordance with the operation of suitable power switch machines such, for example, as the switch machine shown in the patent to W. K. Howe, Patent No. 1,466,903, dated September 4, 1923.

The control panel of the control machine has constructed thereon a miniature track diagram as illustrated in Fig. 6A corresponding to the track layout in the field for which the system is provided, such diagram comprising translucent linear inserts such as inserts 2ANK and 3NK spaced along the trackway of the diagram for indicating various conditions of the system so as to be of material assistance to an operator in the intelligent operation of the control machine for the establishment of routes. The construction of the diagram and the mounting of indicator lamps behind the control panel for the illumination of the inserts can be provided, for example, as shown in the prior patent of Merkel, Pat. No. 2,317,472, dated April 27, 1943. In the portions of the trackway corresponding to the ends of the routes, buttons are provided by which an operator can manually designate the entrance and exit points for routes to be established. Separate entrance and exit buttons NB (see Fig. 6A) and KB respectively have been provided for the various route ends, but it is to be understood as has been pointed out in the above mentioned Judge patent that single buttons for the defining of the route ends for routes to be established could be employed with suitable contacts and circuit control means to provide distinctive entrance and exit designation in accordance with the sequence of operation of the buttons in defining the ends of routes to be established.

Switch position selecting Or switch control relays are provided for the respective normal and reverse positions of the respective crossovers and the single track switch. A relay AN (see Figs. 1A and 1B) is associated with the left-hand or upper end of each of the crossovers for the normal position of the track switches thereof, and a relay BN is associated with the opposite end of each of the crossovers for a similar purpose. A

single track switch has a normal switch control relay N associated therewith for governing its normal position. Each of the crossovers and the single track switch has a reverse switch position selecting relay R for governing the reverse operation of the switch machines associated with the respective crossovers and the single track switch.

A neutral polar relay WZ (see Fig. 2) is provided for eachof the crossovers and for thesingle track switch for more directly governing the power operation of the switch machines, such relay being responsive to the switch position selecting relays associated with that particular crossover or single track switch. Each of the crossovers and the single track switch has associated therewith a neutral polar relay WP for repeating the mechanically locked position of the switch points of the associated track switches in their normal or reverse position. Relays NOR and ROB are associated with each crossover and with the single track switch for repeating the respective normal and reverse correspondence conditions of the switch position selecting relays and the WP relay ior the corresponding crossover or single track switch.

Normally energized track relays TR (see Fig. 4A) and track repeater relays Tl? together with rear release route locking relays ES (see Fig. 5) and WS are provided in the usual manner as fully disclosed in the above mentioned Judge patent.

Having thus considered the apparatus and its general application for this embodiment of the present invention, it is believed that the mode of operation of the system and principles involved together with the circuit structure can best be understood upon reference to certain specific typical operatin conditions of the system.

Operation As a basis of consideration of various typical operating conditions of the system, certain conditions are assumed as normal. The normal conditions of the system as illustrated are said to exist when the indicator lamps governing the lilumination of the translucent inserts on the control panel are dark to indicate that there are no routes established through the track layout, or partially established, that the signals are all at stop, and that each of the track sections in the track layout is unoccupied. The track switches under normal conditions are in their normal positions because it is assumed that the last routes that were established through the track layout require such track switches to be in those positions. The relays associated with the means provided for the automatic selection of the routes responsive to manual entrance and exit designation of the route ends by the actuation oi the respective entrance and exit buttons are all normally deenergized, and only those relays associated with the track circuits and the locking such as the relays WP, TR, L, ES and WS are normally energized.

Route establishment-The circuits for the relays associated with the selection of each of the routes are provided in the form of circuit networks (see Figs. 1A and 1B) there being a circuit network conveniently called an initiating circuit network" for each direction of trafllc, and a circuit network conveniently called a completion circuit network" used in the establishment of routes for either direction of traific.

Each of the initiating circuit networks has circuit portions corresponding to the various track portions at the track layout, and the organization of the circuits is such that feed points for such circuit networks are provided at points corresponding to the entrance ends of the routes. Thus, the energization of an entrance relay NR responsive tgthe manual designation of an entrance point by the actuation of the entrance button NB for such point causes energy to flow through each of the circuit portions of the initiating network provided for that direction of traffic, only so far as such portion corresponds to a route in the track layout which is available for use. Included in each networks is a conditioning relay Y for each of the track switches connected in the circuit network in such a manner that such relay can be energized only when there is an available route extending from a designated entrance point over that track switch in a normal position. Although this condition is generally true, it is to be understood that under certain conditions it may be desirable that certain of the relays Y be connected in the circuit network in such a manner that they can be energized only when there is an available route extending from a designated entrance point over that track switch in a reverse position.

The completion circuit network is provided for the energization of the switch position selecting relays N, AN, BN and R, and such circuit network is energized dependent upon the energization of the various exit relays XR which are picked up in response to the manual designation of the corresponding exit points of the routes, subsequent to the designation of the entrance end of such routes, by the actuation of the buttons be longing to such exit points. An exit relay XR when once picked up is maintained energized over an initiating circuit network when the route is established, but only until such route is entered by a train.

Responsive to the picking up of a normal or a reverse switch position selecting relay in the establishment of a route, the W2 relay belonging to that crossover or single track switch is energized with a polarity to cause by the positioning of its polar contacts the power operation of the track switches or the single track switch with which it is associated. The manner in which the relay ZWZ is controlled to correspond with the normal or reverse condition selected by the switch position selecting relays ZAN, 2BN and 2B is illustrated in Fig. 2 and is fully described in the above mentioned Judge patent. It will be noted that the circuit organization is such that the relay ZWZ is picked up responsive to the picking up of a switch position selecting relay only when the positions of the track switches of the crossover 2 are out of correspondence with the position selected by the switch position selecting relays. Thus, when a correspondence condition is assumed, the relay ZWZ is dropped away.

After the track switches of a crossover have been positioned to correspond with the position required for a route to be established, a correspondence relay NCR or RCR is picked up, the circuits being illustrated in detail as typical for the relays ZNCR and IRCR associated with the crossover 2.

The inclusion of contacts of the correspondence relays NCR and RCR in the circuits for the energization of the signal control relays G illustrated in Fig; 3 provides that after a route has been completely established, a signal control relay G is picked up for causing the proceed indication of the signal governing entrance to the route, such indication being clear or caution in accordance with the proceed or stop condition of the signal in advance as selected by a, relay GYP associated with such advance signal.

Upon the operation of a signal mechanism to a proceed indicating position, the approach lockof the initiating circuit ing stick relay AS (see Fig. for that signal is deenergized, and the dropping away of that relay is effective to cause the tumble-down of the normally energized route locking stick relays ES or WS for the particular direction of traffic of the route which has been established, a route locking relay being dee'nergized for each track section included in that route.

To consider a bit more specifically the mode of operation of the system upon the establishment of a route it will be assumed that an operator desires to establish 'a route to extend from signal II to signal I6. Thus he depresses the entrance button IINB to initiate the establishment of the route at a time when the normal conditions of the system prevail as they have been described.

Responsive to the depression of the button IINB (see Fig. 6A), the entrance relay IINR (see Fig. 1A) is picked up and maintained energized by its stick circuit dependent upon the unoccupied condition of the track section immediately in advance of the entrance point. A front contact of relay IINR applies energy to the initiating circuit network for eastbound traffic, and such energy in feeding through the network causes the picking up of the relays 3Y and BY thus completing connections by which energy can flow to the relays I3XR and KR to condition such relays so that they can be picked up if an operator depresses the corresponding exit button XB.

Assuming the operator to depress the button HXB (see Fig. 6A) after the relay MXR (see Fig. 13) has been conditioned for energization by energy feeding through the initiating circuit network, the relay HXR is picked up, and a stick circuit is closed to maintain such relay energized dependent upon energy feeding through the initiating circuit network from a front contact of the entrance relay HNR.

Responsive to the picking up of relay MXR, energy is applied to the completion circuit network to cause the picking up of the switch position selecting relays to correspond with the preselection of the route as effected by the energize,- tion of relay BY in the initiating circuit network. The energization of that relay has determined that the relay 4BN is picked up in preference to the relay 4R upon application of energy to the completion circuit network by the picking up of the relay MXR. Upon picking up of relay BN energy is fed through the comple tion network to cause the picking up of relay 2R, such relay being selected in. preference to relay 2BN by the dropped away condition of the relay ZBY in the initiating circuit network for eastbound traffic. In accordance with the energization of the relays 2R and EN, the track switches of the crossovers 2 and 4 respectively are power operated to corresponding respective reverse and normal positions. Inasmuch as it is assumed that the track switches of the crossovers are normally in alignment for through traffic on the two main tracks, the track switches of crossover 4 are already in their normal positions, and the relay 4WZ (not shown) governing the power operation of the track switches of that crossover is not picked up responsive to the energization of the relay lBN. It is required, however, that the track switches of crossover 2 be operated to their reverse positions in accordance with the energization of relay 2R, and therefore the picking up of relay 2R causes the picking up of the relay 2W2 (see Fig. 2) tor applying energy. to the switch machines ZASM and 2BSM for causing th power operation of the track switches 2AW and 2BW to their reverse positions. When such such relay being energized by a.

In accordance with the operation of the mechanism of signal H to a proceed indicating posion, the relay IIRGP is dropped away (see Fig. 4B) and the dropping away of such relay is effective to cause the dropping away of the approach locking stick relay HAS (see Fig. 5). Upon the dropping away of relay HAS, the

tumble-down of the route locking relays is ini-- tiated, such relay opening the circuit for the relay 3E8. The dropping away of relay 3E8, with the track switches of crossover 2 in their reverse positions, causes the release of relay QES, the release of such relay being effective to cause the dropping away of the relay .illES associated with the track section lilT which is the end section in the route which has been assumed to have been established.

In addition to the route establishing means responsive to the entrance and exit buttons for the ends of the routes, auxiliary switch control means is provided in the form of auxiliary switch control levers SML for the respective crossovers and the single track switch as illustrated in Fig. 6A. By these levers it is provided that an operator can cause the power operation of the single track switch or of the track switches of either selected crossover as desired without the manipulation of the respective entrance and exit buttons to establish a route. The manner.

in which the track switches of crossover 2 can be operated to their normal and reverse positions in accordance with the positioning of the auxiliary switch control lever ZSML is illustrated in Fig. 2 as typical of the auxiliary control provided for the track switches of the crossover 4. and for the single track switch 3.

Restoration.By the use of stick signals in.

combination with rear release route locking, the parts of the system that are associated with portions of a route becoming unoccupied in the rear of a train are restored to normal as the train progresses through the route. To consider, for example, a specific condition of restoration in the rear of a train, it will be assumed that a train accepts the signal II when a route has been established from such signal to signal i6 via crossover 2 in a manner which has been described. The passage of the train into the track section 3T causes the dropping away of the relay IINR (see Fig. 1A) for the entrance end of the route; and the dropping away of such relay is effective to cause the release of the exit relay MXR (see Fig. 1B) for the exit end of the route. The deenergization of the exit relay MXR, however, does not cause the dropping away of the switch position selecting relays 4BN and 2R as such relays are maintained picked up by stick circuits dependent upon the route looking as typically shown in Fig. 2 for the energizatlon of the lower winding of relay 2R. The relays BN and 2R therefore are maintained picked up until the route locking for their detector track sections is restored.

As the train progresses further through the route so as to leave the track section 3T unoccupied in the rear of the train, the route locking 5 relay 3E8 (see Fig. 5) is picked up, and in a similar manner when the track sections ST and HIT become respectively unoccupied in the rear of the train the route locking relays 9E8 and WES belonging to such track sections are energized.

Inasmuch as the relay 2R has energy applied to its stick circuit (see Fig. 2) whenever either relay 3E8 or relay 9E8 is deenergized, the relay 2R ismaintained picked up until the track section 9T has become unoccupied in the rear of the eastbound train, such relay being restored at that time. The relay 4BN is dropped away when the relay IBES is picked up upon the track section NT becoming unoccupied in the rear of the eastbound train, thus completing the restoration to normal of the various parts of the system associated with the establishment of the route under consideration.

Indications-The indications provided by the present invention are definite and complete so that an operator can be best informed of conditions which he must consider in the designation of the ends of routes to be established, and in the auxiliary control of the track switches. The system therefore provides for the indication of an established route by the illumination of translucent inserts in the control panel to provide an effectively continuous line of light, such indication being displayed immediately upon the selection of a route by the switch position selecting relays prior to the power operation of the track switches to establish such route. The passage of a train through a route which is set up is indicated by the illumination of the inserts corresponding to the occupied track sections by red lamps as compared to white lamps used for the illumination of the inserts for track portions corresponding to unoccupied established routes.

If a single track switch or a crossover is out of. correspondence with the positions called for by the switch positioning selecting relays, the translucent insert included in the portion of the track diagram corresponding to the route selected for the indication of the switch position is flashed to; indicate that correspondence has not yet been established in accordance with the required position for the route to be set up. Such flashing continues only so long as the single track switch or crossover is out of correspondence with the position called for by the switch position selecting relays. It is also provided that the dropping away of the relay W? for a single track switch or a crossover because of such track switch becoming abnormally unlocked at any time, irrespective of whether or not there is a route established over such track switc Inn will cause the flashing of the translucent inserts for both the normal and reverse positions of the single track switch or the track switches of the crossover involved, thus, providing a distinctive out-of-correspondence indication from that provided by the temporary out-of-correspondence condition prevalent in the normal course of operation of a track switch in the establishment of a route.

The indication system provided by the present invention provides for the illumination of trans lucent inserts for the track portions other than those used for indicating the normal and reverse positions of the track switches by the energizats tion of white lamps for such inserts only responsive to the establishment of routes by entranceexit designation. Such arrangement therefore provides that the actuation of the respective auxiliary control levers SML for the various track switches effects the energization of only the white lamps associated with indicating the positions of the track switches involved. It is provided, however, that the translucent inserts other than those employed for indicating the positions of the track switches are illuminated by the energization of red lamps for such inserts in case of a track circuit failure for the corresponding track sections, or in case of passage of a train when a route has not been established by the route establishing means, as can be eflectedflorrexample, by the positioning of the track switches by the auxiliary control means to establish a route for the passage of a train by hand signal.

For an understanding of the circuit organization provided for the energization of the indicator lamps to furnish the desired distinctive indications heretofore considered in a general manner, assume that a route is established through the track layout illustrated in Fig. 4A extending from H to M via crossover 2. With reference to the track diagram illustrated in Fig. 6A, the approach of the train to signal H is indicated when the train enters the approach track section by the illumination of the translucent insert HAPK in accordance with the energization of a red lamp llAPK-R by an obvious circuit closed at back contact 40 upon the dropping away of the track relay 2TB for the approach track section.

When the exit relay I4XR is picked up subsequent to the depression of button I4XB for the establishment of the route, energy is applied to the circuit network for the energization of the indicator lamps at front contact 4| (see Fig. 6B). Thus the lamp 4BN/RK-W for the illumination of insert 4BN/RK is energized by a circuit ex tending from including front contact 4| of relay I4XR, front contact 42 of relay lllTP, and lamp 4BN/RK-W, to In accordance with the energization of relay 4BN and the picking up of relay 4NCR in the establishment of the route, a circuit is closed to cause the energization of the lamp 4BNK-W for the insert 4BNK, such insert being used in indicating the normal positions of the track switches of crossover 4. Such circuit extends from including front contact 4| of relay l4XR, front'contact 42 of relay IBTP, contact 43 of lever 4SML in its center position, front contact 44 of relay 4NCR, front contact 45 of relay 4BN, and lamp 4BNK--W, to

The picking up of the relay 4BN causes energy to feed further through the circuit network to cause the energization of the lamp 2BN/RK-W for the insert iBN/RK by a circuit extending from (-1-), including front contact 4| of relay IGXR, front contact 42 of relay IBTP, front contact 46 of relay IllTP, front contact 41 of relay 4BN, wire 48, front contact 49 of relay BTP, and lamp 2BN/RK-W, to

Inasmuch as it has been assumed that the track switches of crossover 2 are required to be operated from their normal to their reverse posi tions for the establishment of the route, the picking up of the relay 2B in accordance with the route selected, with the relay IRCR dropped away, causes the flashing of the lamp 2BRK-W for the insert 2BRK by the intermittent enersization of a circuit extending from, {FY-tirincludlng back contact 50 of relay ZRCR, front contact of relay IR, and lamp ZBRK-W, to The lamp 2ARKW for the insert 2ARK is also flashed by the energization of a corresponding circuit. 5

Responsive to the picking up of the relay 2R in the establishment of the route a circuit is closed for the energization of the lamp ZAN/RIC-W for the insert 2AN/RK extending from (-H, including front contact 4! of relay I4XR, front contact 42 Of relay lllI'P, front contact 46 of relay IOTP, front contact 41 of relay 4BN, wire 48, front contact 49 of relay 9TP, front contact 52 of relay STP, front contact 53 of relay 2R, front contact 54 of rela 31?, and lo lamp 2AN/RK--W, to

When the track switches of crossover 2 have been operated to their reverse positions and locked, the reverse correspondence relay IRCR is picked up, and the picking up of such relay opens the circuits by which the reverse position indicator lamps for the crossover have been energized intermittently and closes a circuit for the steady energization of lamp 2BRK-W for the insert 2BRK extending from includin front contact 4| of relay MXR, front contact 42 of relay IUTP, front contact 45 of relay lllTP, front contact 41 of relay 4BN, wire 48, front contact 49 01' relay 91?, contact of lever ZSML in its center position, front contact 50 of relay a0 IRCR, front contact 5| of relay 21R, and lamp IBRK-W, to A circuit is also closed at the same time for the steady energization of the lamp 2ARK-W for the illumination of the insert 2ARK extending from including front 35 contact 4| of relay I4XR, front contact 42 of relay IIITP, front contact 46 of relay IOTP, front contact 41' of rela 4BN, wire 48, front contact 49 of relay 91?, front contact 52 of relay STP, front contact 53 of relay 2R, front contact 54 40 of relay 31?, contact 56 of lever ISML in its center position, front contact 51 of relay ZRCR, front contact 58 of relay 2R, and lamp 2ARK--W, to (-J.

By the energization of circuits which have 5 been described, lamps are illuminated to cause in effect a continuous line of light to be displayed along the track diagram to correspond with the route which has been established. In accordance with the clearing of the signal II governing entrance to such route, the route locking becomes effective, and the dropping away of the relay MES for the track section IOT adjacent the exit end of the route applies energy to the circuit network in multiple with front contact 4| of relay 56 KB at back contact 59 to maintain the circuit network energized after relay I4XR has been dropped away upon the entrance of the route by a train.

Assuming an eastbound train to accept the .0 signal H and enter the route, the dropping away of the relay 3IP opens the circuits which have been described for the lamps 2AN/RK-W and 2ARK-W at front contact 54, and by the clo sure of back contact 60 of relay 3TP energy is I! applied by obvious circuits to the lamps ZAN/RK-lt and LARK-R for the corresponding translucent inserts. the lamp 2ANK-R remaining dark because of the opening of its circuit at back contact 6| of relay 2RCR. Thus the 70 energization of red lamps for the inserts ZAN/RK and IARK indicates that the train has entered the route but that the track section 9T has not yet become occupied.

Upon passage of the eastbound train into the TI track section 9T, the dropping away of relay STP causes the extinguishing of the lamp 2BN/RK--W and 2BRK-W by the opening of front contact 49, and the closure of back contact 62 of relay QTP applies energy to obvious circuits for the illumination of the red lamps 2BN/RKR and 2BRK-R for the inserts 2BN/RK and 2BRK. The lamp 2BNK--R is maintained dark because of the opening of its circuit at back contact 63 of relay ZRCR.

Upon further progress of the train so as to cause the track section 3T to become unoccupied in the rear of the train, the lamps ZAN/RK-R and 2ARK-R are extinguished upon the opening of back contact 60 of relay HP, and the white lamps for the corresponding inserts remain dark because the circuits which have been described for such lamps are maintained opened by the opening of front contact 49 of relay QTP, or the deenergization of any track relay in the portion of the route extending in the direction of the exit point from the track section 3T with which the lamps for the energization of inserts 2AN/RK and 2ARK are associated. It will be noted that the red lamp for the insert ZBRK is maintained energized as long as the track section ST is occupied by the train, and the illumination of such insert is an indication to the operator that the track switches of crossover 2 are maintained locked in their reverse positions, and a route cannot be established using the normal position of the track switch at the A end of that crossover.

When the track section HIT becomes occupied by the train, the opening of front contact 42 of relay IBTP causes the extinguishing of lamps 4BN/RK-W and 4BNK-W, and the inserts 4BNK and 4BN/RK become illuminated by the energization respectively of the red lamps 4BNK-R and 4BN/RK--R by obvious circuits closed at back contact 64 of relay HITP. The lamp 4BRKR is maintained dark in accordance with the opening of its circuit at back contract 65 of relay 4NCR.

When the track section 9T becomes unoccupied in the rear of the train, the opening of backcontact 62 of relay 9'IP causes the extinguishing of the red lamps for inserts 2BRK and 2BN/RK, and the white lamps for such inserts are maintained dark in accordance with the opening of front contact 42 of relay IIITP in the circuit network for the energization of such lamps.

When the eastbound train leaves the route entirely so as to cause the picking up of the relays IDES and IUTP, energy is removed from the circuit network for the energization of the indicator lamps corresponding to the route which has been considered, and the opening of back contact 64 of relay lll'I'P causes the extinguishing of the red lamps 4BN/RK-R and 4BNK-R for the inserts 4BN-RK and 4BNK respectively. It will, be noted that the relay IUES responds to the picking up of the track relay lll'I'R (see Fig. 5) and the relay IOTP is also picked up responsive to the picking up of the relay HI'I'R. (see Fig. 4A). Thus, inasmuch as it is desirable that the relay MES be picked up prior to the picking up of relay illTP to prevent a flash of the white lamps for the inserts 4BN/RK and 4BNK, the relay IIJ'IP is made to have relatively slow pick-up characteristics.

Another means which can be employed to prevent the flash of the white lamps under such condition more positively is to apply energy to the circuit network by a back contact of the route locking stick relay 9ES or 3E8, selected by the correspondence relays of crossover 4, instead of by the back contact 59 of relay IDES. If this were done, the relay 9228, for example. for the route which has been considered would have been picked up as soon as the track section 9T became unoccupied in the rear of the train, and there- ,fore the picking up of such relay would remove energy from the circuit network for the energization of the white indicator lamps prior to the picking up of the relay IDTP, the relay IBTP being picked up only after the route had become entirely unoccupied in the rear of the train.

By the use of route locking stick relay contacts as auxiliary feed points for the ends of the circuit network for the energization of the white indicator lamps, the system is adapted to indicate properly the portions of routes which are maintained established by the route locking where back-up train movements are involved.

More specifically, for example, assume that a train having entered a route extending from II to HI via crossover 2 as has been described desires to reverse its direction, such train occupying the track'section 3T, and the track section 9T, and perhapseven the track section HIT. When the train reverses its direction, according to the well known circuit organization of the rear release route locking, the route locking relay IRES for the track section lllT cannot be restored until the train which has reversed its direction has left the route so as to allow the picking up ofrthe track relay 3TB for the track section 3T adjacent the entrance end of the route. As the track sections l and BT become unoccupied in the rear of the train, the closure of front contacts 42 and 49 of relays HTTP and BTP respectively is eliective to cause the circuit network to build up from the exit end of the route, and the closure of back contact 59 of relay HTS is effective to apply energy to that portion of the circuit network to cause the energization of the white indicator lamps for the portions of the route become unoccupied in the rear of the train, and which are maintained established until the entire route has become unoccupied. This is a desirable mode of operationbecause an operator should be informed that the portion of the route under consideration is maintained locked in order that he will not attempt to establish routes in conflict with such portions. It will be noted that if the circuits were modified as has been described so as to cause the contact 59 of relay IDES to be replaced by a back contact of the relay BES selected by the correspondence relay NCR, energy would be applied to the circuit network to provide the same mode of operation which has been described, the

relayv 9E3 under such conditions being effective to apply energy to the circuit network at the point to which .the back contact as of relay IUES is connected until the route were completely unoccupied by the tarin making the back-up train movement.

Although the White lamps are connected in the circuit network for route indications, it, is provided by the use of contacts of the auxiliary switch control levers SML that the lamps for indicating the positions of the track switches of the respective crossovers and the single track switch are disconnected from the circuit network when such track switches are operated in accordance with the positioning of the corresponding auxiliary control levers.

More specifically, the white lamps 2ARKW and ZANK-W, for example, for the track switch atthe left-hand end of the crossover 2 are enersized by the circuit network only in accordance with the closure ofrcontact B of lever ZSML in its center position. Thus, if an operator actuates the lever ISML to its right-hand position for the power operation of the track switches of the crossover 2 to their normal positions, the contact 55 is shifted to its right-hand position to open the connection of the lamps 2ANKW and ZARK-W to the circuit network, and close a circuit by which the lamp 2ANK-W is energized upon the response of the relays 2AN and 2NCR. Such circuit extends from including contact 56 of lever 2SML in its right-hand position, front contact 51 of relay ZNCR, front contact 68 of relayIA'N, and lamp IANK-W, to If the track switches of crossover 2 are not already in their normal positions when the auxiliary control lever is operated, the relay ZAN is picked up prior to the picking up of relay 2NCR. and the lamifZANK-W is flashed until the correspondence relay 2NCR is picked up by the energ'ization of a circuit extending from (F-i-l including back contact 5'! of relay ZNCR, front contact B8 of relay 2AN, and lamp 2ANK-W to Inasmuch as the relay 2BN is also responsive to the operation of the auxiliary switch control lever 2SML to its normal operating position. the lamp 2BNK-W is illuminated in a manner and by a circuit'organization corresponding to that which has been described for the lamp 2ANKW for the opposite end of the crossover.

Ifthe auxiliary control lever ZSML, for-en ample, is operated'to its left-hand position for causing the track switches of the crossover 2 to be power operated to their'reverse positions. the lamps 2ARK-W and 2BRK-W become il1uminated. Such lampsare flashed until the track switches of the crossover obtain their correspondence positions by the energization of circuit: which have been described. The lamp 2ARK-W becomes steadily energized "upon the picking up oi the relay ZRCR by the energization of a cir cult, extending from including contact 56 of lever '2SML ln'its left-hand position, front con tact 51 of relay 2RCR, front contact 58 of relay 2R, and lamp 2ARKW, to ('-l. The lamp 2BRK- -W is energized by a corresponding circuit extending from (-1-) including contact 55 of lever ISML in its left-hand position, from; contact 50 of relay 2RCR', front contact 5| of relay 2R, and lamp IBRK-W, to

It willjbe noted that because of the isolation of the circuits for the switch indication lamps iro'mthe network by the center contacts of the auxiliary controilever's when they are actuated to controlling positions, energy is prevented from feeding back onto the network to cause the energization of lamps notdesired to be energized, such, for example, as the lamps adjacent the route ends and between the track switches which are not used for switch position indications.

In case of track circuit failure at a time when a route is established, the red lamps are iiluminated for the insertsin the established route corresponding to the track section involved in th tailurarapd it is further provided that a track circuit failure when'a route is not established will be indicated by the illumination of the red lamps for all inserts used in connection with indicating occupancy of that track section. For example, the dropping away of relay 31? when there is no route established and the correspondence relays INCR andlRCR are in their normally deenergized positions, causes, by the closure of back contact 80, the energization of the lamps iAN/RK-R, 2ANKR and 2ARKR to call to an operators attention the abnormal condition.

Another object in controlling the red indicator lamps a shown and described is to provide a means by which the passage of trains by hand signal through the routes can be indicated on the control panel, the track switches being aligned by the auxiliary switch control means, and displaying switch position indications for such route.

When a track switch becomes abnormally unlocked, a distinctive indication is provided by the flashing of both the normal and reverse white in dicator lamps for such track switch, or for both track switches of a crossover if it is a track switch of a crossover that is involved. Thus, for example, if a track switch of crossover 2 becomes unlocked when there is no route established over the crossover energy is applied to the lamps 2ANKW, 2ARKW, 2BNK-W and ZBRK-W. The lamp ZANK-W is intermittently energized under such conditions by a circuit extending from (F+), including back contact 69 of relay 2WP, back contact 18 of relay 2WZ, back contact 68 of relay 2AN, and lamp 2ANK-W, to The lamp 2ARKW is intermittently energized under such conditions by a circuit extending from including back contact 69 of relay 2WP, back contact 10 of relay 2W2, back contact 58 of relay 2R, and lamp IARK-W, to The lamp 2BNKW is energized under such conditions by a circuit extending from (F+), including back contact 69 of relay ZWP, back contact 10 of relay 2W2, hack contact H of relay ZBN, and lamp ZBNK-W, to The lamp 2BRK-W is intermittently energized under such conditions by a circuit, extending from (F+), including back contact 69 of relay ZWP, back contact 10 of relay 2W2, back contact 5| of relay 2R, and lamp 2BRKW, to It will be noted that the circuits described are not closed during the usual power operation of the track switches, because, although the relay ZWP is dropped away at such times, the relay 2WZ is picked up to open the circuits which have been de scribed at back contact 10.

Having described a system for providing control panel indications in a particular entranceexit system as applied to a particular relatively simple track layout as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the present invention rather than to limit the number of forms which such invention may assume; and, it is to be further understood that Various adaptations, alterations and modifications may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What we claim is:

i. In a switch and signal control system for railway track layouts comprising a plurality of detector track sections interconnected by track switches to afford various routes, certain of the routes including a plurality of detector track sections, a miniature track diagram of the track layout including indicating means for illuminating portions of the represented track to outline the portions of a route established over each track section while it is not occupied, normal and reverse switch control relays associated with each switch for governing the power operation thereof to the normal and reverse position, route establishing means responsive to the manual designation of the entrance and the exit end 01' a desired route for energizing the switch control relays of the appropriate switches as required to establish such route, a circuit network for lighting the lamps of said indicating means for each track section included in a route when that route is selected by said route establishing means and for maintaining said lights lighted for track sections ahead of a train traversing such route, said circuit network having feed points correspondin to certain locations constituting the exit ends of the routes and including front contacts of the switch control relays to form a route circuit path conforming with each route as it is selected by the energization of said switch control relays, said circuit network also including contacts associated with each of said detector track sections and opened when that track section is occupied, means for energizing the feed point of said circuit network corresponding to the exit end of a route selected by said route establishing means until that route establishing means is restored to normal manually by the operator or automatically by the entrance of a train into such route, and means for energizing the feed point of said circuit network corresponding to the exit end of a route occupied by a train until that route becomes unoccupied.

2. In a system for governing the display of indications on the miniature track diagram of a railway track layout comprising detector track sections interconnected by track switches to afford various routes, certain of the routes including a plurality of detector track sections, a miniature track diagram of the track layout including indicating lamps for illuminating substantially linear portions of the represented track on said track diagram to outline a route, manually operable means associated with said miniature track diagram for governing the power operation of the track switches to select any desired route, lighting circuits including contacts operated in accordance with the controlled position of those switches included in a detector track section for selectively lighting indicating lamps to illuminate the track diagram for the portions of a selected route representing that track section, a circuit network governed in accordance with the controlled positions of the switches included in a selected route to provide circuit paths conforming with such route, said circuit network including in series two contacts associated with each detector track section and both opened when that track section is occupied and connected to said lighting circuits at points between said contacts, and means for energizing said network at a feed point corresponding with the exit end of any given route selected by said manually operable means for train movement in either direction after a train has entered such route and until that route becomes unoccupied.

3. An indication display arrangement for switch and signal control systems of the entrance-exit type for a track layout having detector track sections interconnected by track switches to afford various route comprising, a miniature track diagram of the track layout including indicating means having lamps to illuminate substantially linear portions of the represented track to outline the portions of a route established or the portions of a route in advance of a train occupying that route, switch control relays for governing the power operation or the track switches of the track layout, route establishing means responsive to the designation of entrance and exit ends ofany given desired route for energizing the switch control relays of the appropriate track switches as required to establish that route, a circuit network including normally open contacts oi. said switch control relays for roviding circuit paths conforming with each route as selected by the energization of said switch control relays, said network having feed points corresponding with the signal locations constituting the exit ends of said routes, lighting circuits for said indicating lamps connected to said network, contacts in said network associated with each detector track section and when that track section is occupied for interrupting the energization of the indicating lamp for that track section in the route occupied by the train and for interrupting the energization of indicator lamps for all track sections in that route in the rear of such occupied track section, and means for energizing said network at a feed point corresponding to the exit end of any given route established by said route establishing means after said route is occupied by a train and until it becomes unoccupied.

4. In a switch and signal control system for railway track layouts including at least one power operated track switch, a miniature track diagram of said track layout including indicating means for illuminating portions of the represented track adjacent said switch points to show the normal and reverse position of said switch, switch control relay means for governing the power operation of said switch, manually operable means for energizing said switch control relay means to cause power operation of said switch to the normal or reverse position as required, means governed by said manually operable means for rendering effective said indicating means for either the normal or the reverse position of said switch as selected by said manually operable means, a switch position indicating relay energized only if the switch is locked in a normal or reverse position, and means for illuminating both of said normal and reverse indicating means whenever said switch position indicating relay is deenergized while said switch control relay means is not energized, whereby an unlocked condition of said switch occurring when that switch is not being operated under normal conditions is distinctively indicated on said track diagram.

5. In a switch and signal control system of the character described for a track layout providing by power track switches a plurality of conflicting routes extending between entrance and exit points, each route extending through a plurality of track sections; normally energized track relays for the respective track sections; route establishing means including the selective energization of normal and reverse switch control relays for each of the track switches for causing the establishment of each route when it is available in response to the manualdesignation of the entrance and exit ends of that route; a miniature diagram of the track layout having an indicator lamp for each portion of the diagram corresponding to a track section in each of the routes; and a circuit network for the energization of said indicator lamps having circuit portions including front contacts of said normal and reverse switch control relays in such an arrangement as to cause the energization of the indicator lamps only when the track portions with which they are associated are in ill cluded in established routes, such circuit network also lncluding contacts of said track relays in such a manner as to cause energy for each indicator lamp to pass through front contacts connected in series of the track relays for all track sections extending from the section with which such indicator lamp is associated in the direction of the exit end of an established route, whereby the presence of a train in a track section removes energy from the indicator lamps for all track sections in the portion of the route in the rear of the train,"'irrespective of the conditions of said normal and reverse switch control relays.

6. In a switch and signal control system of the character described for a track layout providing by power track switches a plurality of con flicting routes extending between entrance. and exit points, normally energized track relays for detecting occupancy of the respective track sections, route establishing means including the selected energization of normal and reverse switch control relays for the respective track switches for causing the establishment of each route when it is available responsive to the manual designation of the entrance and exit ends of that route, an indicator lamp for each of the track sections, and circuit means for energizing each of the indicator lamps when its track section is included in an established route, such circuit means including in series vfront.con tacts of said track relays for each of the track sections in the portion of the established route extending from the track section with which such lamp is associated to the exit end of that route, whereby the presence of a train in any track section of a route opens the circuits for indicator lamps associated with track sections of the route in the rear of the train irrespective of the condition of said normal and reverse switch control relays.

'7. In a switch and signal control system for railroads for a track layout providing by a power switch a plurality of conflicting routes extending between entrance and exit points, normal and reverse switch control relays for said track switch, route establishing means responsive to the manual designation of the entrance and exit ends of any available route desired to be established for selectively energizing said normal or said reverse switch control relay in accordance with whether the route to be established requires said track switch to be in a normal or a reverse position, switch operating means responsive to the energization of said normal or said reverse switch control relay for operating said track switch to a corresponding normal or reverse locked position,

a normal indicator lamp for the normal position 0! said track switch, a reverse indicator lamp for the reverse position of said track switch, circuit means for flashing said normal or said reverse indicator lamp when the corresponding normal or reverse switch control relay is energized but said track switch is not locked in the corresponding position, circuit means for flashing both said normal and said reverse indicator lamps when said normal and reverse switch control relays are both deenergized and said track switch is unlocked, and circuit means for steadily energizing said normal or said reverse indicator lamp when a route is established over said track switch in a corresponding position and said track switch is locked in that position.

8. In a system of indication display for interlocking systems, a track layout including a plurality of detector track sections interconnected by power-operated track switches to afford various routes for train movement in either direction, a miniature track diagram of the track layout including a plurality of indicating lamps for each track section for illuminating portions of the represented track to outline a route, manuallygovernable route establishing means for governing the power operation of the track switches to establish any selected route, a circuit network having circuit portions corresponding with the different track sections and controlled by said route establishing means to form a circuit path corresponding to any selected route, a detector track relay associated with each track section, two front contacts of each detector track relay connected in series in said circuit portion corresponding to that track section, lighting circuits for the indicating lamps for each track section selected in accordance with the controlled positions 01' the switches for that section and connected to said circuit network between said two track contacts of the corresponding track relay, and circuit means for applying energy to said circuit network at feed points corresponding with operated track switches, a miniature track diagram of said track layout including a plurality of indicating lamps, the selective energization of which provides for the illumination of portions of the represented track adjacent any represented track switch to indicate the normal or reverse position of that switch included in a selected route, manually governable route establishing means for governing the power-operation of the track switches to establish any selected route and including switch control relay means individual to each power-operated track switch, circuit means governed by said route established means for energizing the appropriate indicating lamps to illuminate the normal or reverse posttions of the switches included in any selected route, a switch position indicating means for each power-operated switch for indicating the normal or reverse locked position 01' that switch or its unlocked condition, and circuit means associated with each power-operated switch for energizing the indicator lamps for both positions of that switch whenever said switch position indicating means indicates that switch to be unlocked, said circuit means including back contacts of said switch control relay means for that switch, whereby the unlocked condition of any switch under manual control by said route establishing means is not indicated, but whereby the unlocked condition of any switch not being manually governed by said route establishing means effects a distinctive indication associated with that switch on said track diagram.

NEIL D. PRESTON. FOREST B. HITCHCOCK. 

